The adeno-associated viruses (AAV) which are human parvoviruses that depend on coinfecting helper viruses for their replication, are thought to be non-pathogenic (Siegi et al., 1985, Intervirology, 23:61-73, Berns et al. 1987, Adv. Virus Res. 32:243-306) but rather to exhibit tumorsuppressive properties (Rommelaere et al., 1991, J. Virol. Methods 33:233-251). The virus may persist in infected individuals, possibly by integration of its DNA into specific chromosomal sites of the host cell genome as seen in cell culture. Recent studies of our laboratories have demonstrated that AAV is able to induce differentiation in a variety of cells of human and mouse origin (Klein-Bauemschmitt et al., 1992, J. Virol. 66:4191-4200) including embryonic stem cells. In the course of looking for putative targets of AAV infection, we analyzed material from spontaneous abortion for the presence of AAV DNA using for example the polymerase chain reaction (PCR), the Southern blotting technique and the in situ hybridization technique. Additionally, we analyzed serum samples from women with miscarriage and from other diseased or healthy women for the presence of antibodies to AAV using serological standard techniques such enzyme linked immunosorbent assay (ELISA), fluorescenceimmuno assay (FIA), radioimmune assay (RIA) or immunofluorescence assay (IFA).
Surprisingly, we found a significant correlation of both detectable AAV DNA in samples of abortion material and detectable IgM antibodies directed to AAV with the early abortion occurring during the first trimester of pregnancy. Accordingly, the present invention relates to a method of detecting the causative agent of spontaneous abortion.